Informatica server "session expired due to inactivity. redirecting to the login page". error from the webpage when connected via ltm

HI F5 geeks, I have a informatica server added as a ltm pool member and having http and tcp profiles at virtual server on port 80. when i try to connect via virtual, it connects perfect. After passing login login credentials successfully, it throws the error as " session expired due to inactivity. Redirecting to login page." message from webpage. But there is no issue if i connect directly to the server. ltm version 12.1.2. Appreciate your help.